Atresia is a condition in which a body orifice or passage in the body is abnormally closed or absent.

Examples of atresia include:

  • Imperforate anus - malformation of the opening between the rectum and anus.[1]
  • Microtia- Absence of the ear canal or failure of the canal to be tubular or fully formed[2] (can be related to Microtia- a congenital deformity of the pinna (outer ear).)
  • Biliary atresia - Condition in newborns in which the common bile duct between the liver and the small intestine is blocked or absent.[3]
  • Choanal atresia - blockage of the back of the nasal passage, usually by abnormal bony or soft tissue.[4]
  • Esophageal atresia - affects the alimentary tract causing the esophagus to end before connecting normally to the stomach.[5]
  • Intestinal atresia - malformation of the intestine, usually resulting from a vascular accident in utero[6]
  • Ovarian follicle atresia, atresia refers to the degeneration and subsequent resorption of one or more immature ovarian follicles.[7]
  • Pulmonary atresia - malformation of the pulmonary valve in which the valve orifice fails to develop.[8]
  • Tricuspid atresia - a form of congenital heart disease whereby there is a complete absence of the tricuspid valve. Therefore, there is an absence of right atrioventricular connection.[9]
  • Vaginal atresia - congenital occlusion of the vagina or subsequent adhesion of the walls of the vagina, resulting in its occlusion.
  • Potter sequence - congenital decreased size of the kidney leading absolute no functionality of the kidney, usually related to a single kidney.


  1. ^ Kaneshiro, Neil. "Imperforate Anus". PubMed Health. Retrieved 11 September 2012. 
  2. ^ Bonilla, Arthuro. "Microtia: Congenital ear deformity Institute". Congenital ear deformity Institute. Retrieved 11 September 2012. 
  3. ^ Zieve, David. "Biliary atresia". PubMed Health. Retrieved 11 September 2012. 
  4. ^ Zieve, David. "Choanal atresia". Pubmed Health. Retrieved 11 September 2012. 
  5. ^ Dugdale, David. "Esophageal atresia". PubMed Health. Retrieved 11 September 2012. 
  6. ^ "Intestinal atresia". Pedisurg. Retrieved 11 September 2012. 
  7. ^ Kaipia, A.; Hsueh, A. J. W. (1997). "Regulation of Ovarian Follicle Atresia". Annual Review of Physiology 59: 349–363.  
  8. ^ Schumacher, Kurt. "Pulmonary atresia". PubMed Health. Retrieved 11 September 2012. 
  9. ^ "Tricuspid atresia". PubMed Health. Retrieved 11 September 2012.